CVE-2022-42097: 
PHP vulnerability analysis and mitigation

Backdrop CMS version 1.23.0 was discovered to contain a stored cross-site scripting (XSS) vulnerability via the comment functionality. The vulnerability was discovered on September 27, 2022, and was assigned CVE-2022-42097. The vulnerability affects the commenting system in Backdrop CMS version 1.23.0 (GitHub Release, GrimTheRipper).

The vulnerability allows an attacker to execute stored XSS attacks through the comment functionality. The attack vector requires the attacker to post content in the comment section using the Raw HTML Editor. The XSS payload is executed immediately after saving the comment. The vulnerability specifically affects the comment reply functionality at the endpoint '/backdrop/comment/reply/id_reply' (GitHub CVE).

When successfully exploited, the vulnerability allows attackers to execute arbitrary JavaScript code in the context of other users' browsers who view the compromised comment. This could lead to session hijacking, defacement, or theft of sensitive browser data from users viewing the affected comments (GitHub CVE).

The vulnerability requires an authenticated user account with appropriate permissions to post comments. The attacker must have access to the Raw HTML Editor when posting comments. The exploit is triggered when users view the compromised comment containing the XSS payload (GitHub CVE).

The vulnerability was reported to MITRE on September 27, 2022, and publicly disclosed on October 31, 2022. Users should upgrade to a patched version of Backdrop CMS if available, or disable Raw HTML input in comments if possible (GrimTheRipper).